Box joint



Jan. 10, 1928. 1,655,505

B. A. LANGE I BOX JOINT Original Filed Dec. 24, 1924 4 5 4 2 j 3 1 6 I G 1O 8 I J1 9. 7 8 7 3- 1 1 1 9 5, 0 Fig I gnue'nfo'z, fierf/vo/d 4. Zanye,

Patented Jan. 10,1928.

.nEnrnoLn .A. taxes, or sag Louis. MISSOURI.

- BOX, .rorn r.

"-flriginal applica-tion flied: gllecembewustmljScriaWNo. 757-327. Divided and this application filed p na zsaisas. seriar mz-eaeia' j This invention relates *to joints TfOI'i the edges of boxes formed of pasteboardmfiber board,andsimilarwmateiiial, the present application being a division of my prior a plication for box-joints, Serial 757,827, filed December 24, 1924.

The principal object of the present invention is the provision of a novel form of joint or seam which will leave the material with greater tensile strength than the forms of seams hitherto in use. Other objects and advantages will appear in the course of the following description.

In the accompanying drawings forming part of this specification, in which like numbers of reference denote like parts wherever they occur,

Figure 1 is an end view of a sheet of material creased to form one embodiment of the seam of this invention;

Figure 2 is an end view of the same sheet as it appears when bent a quarter turn on the said form of seam; s

Figure 3 is an end view of another sheet of material embodying another form of the seam of this invention;

Figure 4 is an end view of the sheet of Figure 3 as'it appears when bent on its seam to form two flaps at right angles to one another; and

Figure 5 is another end-view of the sheet of Figure 3 as it appears when folded a half turn on its seam to form two superposed flaps.

The form of seam depicted in Figures 1 and 2 comprises but a single pair of creases 1 and 2, respectively, the crease 1 being formed on the underside ofthe material 3, and the crease 2 being formed on the upper side of the material 3 in staggered or offset relation to the crease 1. The laminations of the material intermediating the two creases have become sheared or separated from one another by the upsetting action'of the die employed in their formation, those portions of the laminations immediately under the creases 1 and 2 having a curvature which is concentric with their respective creases and which decreases with their remoteness therefrom. In attempting to bend the material at a seam so formed, that particular crease which serves as a center for those laminated portions which are placed under tension by the bending will function largely in preference to the other crease as the principal the seam of axis aboutavhich the; bending occurs. '1 Qtherwise stated, if the left handflapi icoftthe be bent upon any one of three alternative axes, as will be understood by those skilled in the prioriart. Wherever the flap must always be folded upon a definite predeter as in the manufacture of boxes,

mined line,

this invention is essential. It will also be observed that, in the bend exhibited in Figure 2, a reinforcing shoulder 5 on one of the flaps 4: braces the other flap 6.

The small amount of material upset betweenthe closely adjacent creases 1 and 2 in the seam exhibited in Figures 1 and 2, however, allows the pasteboard to bend through more than a right angle with only extreme difficulty. While the seam of Figures 1 and 2, therefore, is preferable for use. where bending at right angles is desired, it is also desirable to have seams which will allow bending with facility through one hundred and eighty degrees, as, for instance, is neces sary for two of the corners in knockdown box construction. the form of seam depicted in Figures 3, 4, and 5 has been produced, the seam'thereof having but one definite axis about which it bends in any one direction, and yet bending easily through a straight angle. This seam is formed by drawing more material thereinto, so as to increase its flexibility. The crease 7 on the underside of the material 8 is sharper or more pronounced than the curvature of the remainder of the seam, so that the material 8 will bend at right angles on a single definite axis with one flap 9 having a shoulder 10 bracing the other flap 11, as shown in Figure 4; or the flap 11 may be bent completely over the flap 9 by reason of the greater flexibility of this seam, as indicated in Figure 5.

In addition to the advantages above enumerated, the seams of this invention, as

determined by actual tests, leavethe material with greater tensile strength than is possessed by similar material creased with the common double joint of the prior art.

Having thus fully described this invention, I hereby reserve the benefit of all changes in form, arrangement, order, or use of parts, as itis evident that many minor changes may be made therein without departing from the spirit of this invention or the scope of the following claim.

I claim A box-j0int comprising a laminated sheet 

